Manufacture of neutral organic sulphur compounds



Patented Oct. 24-, 1944 MANUFACTURE or NEUTRAL ORGANIO SULPHUR-COMPOUNDSHerschel G. Smith, Wallingford, Pa., assigxior w Gulf Oil Corporation,Pittsburgh, Pa., a corporation of Pennsylvania No= Drawing; ApplicationJuly 2,1942, SerialNo. 449,523

13 Claims.

This invention relates to the manufacture of neutral organic sulphurcompounds and compositions containingthesame.

In particular, it relates tot-he manufacture of" synthetic sulphurized'mono-esters' of fatty; acids and compositions containing the same;especially compounded lubricantscomprising a major amountoflubricating'oil and a minor amount of such sulphu'rizedmono-esters; thecompound- 1 ed lubricants having many advantageous propert'ies'and-being useful for various purposes; particularlyin'lubricating'metalsurfaces under ordinary and higher pressures; all asmore fully hereinafter'set for'th and as-clai-me'd'.

More specifically, this'invention is directed to new and improvedmethodsofmaKing sulphurized mono-esters fromglycerides of unsaturatedfatty acids; such-as lard oil and other fattyioils; with recovery ofg'lyce'rine as a valuable byproduct.

In my improved-methods, fatty oils *or glycerides containing unsaturatedfatty acidsare reacted with sulphur 4 to' form sulphur addition productsand-thesul'phurized oils or' glycerides are converted into sulphurizedmono-esters by reaction with a-- monohydric alcohol, advan-- tageouslyin the" presence of" a'- catalyst such as concentrated sulphuric acid;theglyc'eride's being completely decomposed and' jthe'- glycerine beingliberated byalcoholy's'is-of thesulphurized fatty glycerides.

The sulphurized mon'meste'rs so" obtained" are separated from theglycerine: They may be further refined; usually with-activated clay, tore move any deleterious by-p'roclucts if present,

Further, the sulphurized mono-esters may" be blended with minerallubricating oils to obtain variouscompounded lubricants; the sulphurizedmono-esters being-sometimes mixed with mineral oil prior to suchrefining; That is; the present invention achieves various improvementsin mak ing sulphurized mono-e'stersr and 1 utilizing them in lubricantsand'other compositions, the recovery of' valuable glycerinebeing one of"the advan-- tageous features of this invention.

The manufacture ofsulphurized mono-esters of fatty acid andof-lubricatingoil compositions:

containing suchsulphurized' esters are well known. For instance, in myPatents 2,179,060-

and 2,179,-061-, I have described and claimed improvedlubricantscomprising a: mineraloil lubricating baseand a'minor'amount ofsulphurized fatty mono-esters- Asa there' shown, -such lubricants havemany advantageous properties anduses. t

In my Patent 2 179 060 I have specifically claimed l-ubr-icantscontainings sulphurizedsperm oil and: like:mono-este'rs. As therepointed" out sperm oil,,though 'often termed a fatty oil, is

quite differ-entfrom-the ordinary fatty oils which: are-esters ofglycerine-; -sperm 'oili being composed principally of fatty esters of:monohydri'c alco-- hols. Furthertthemonoi-festers of: sperm oil containunsaturated aliphatic groups: and: are capable of reacting with :sulphurto iorm= simple ad-' dition compounds whichare substantially neutral andadvantageous improvement agents in lubricating com-positions: v

Thesup'eriority: of sulphurizedwmono-esters; as a class,. in makingimproved lubricants is further shownin my Patent 2179;061, wherein: Ibroadly claimed improved lubricants: containing thesesulphurized:mono-esters.

In my companion Patents 2,179,065 -and 2,17-9, 0661 have described andclaimed suchsulphurized fatty mono-esters and methods of making thesame. In general, as there shown, su1phurized' mono-esters of fattyacids c'aiib'e" e'as'ily'pre pared by sul huriz'ing' unsaturated fattyor ali ph'ati'cmono estershaving"theformula R el-Mt wherein Rand R"represent straight chainah phatic groups, atleastone of saidgroups beingunsaturated.- In the methods H the said mono-esters are reacted withsulphur-to produce sulphur addition" products; which" are substantiallyneutral ofganidsulpl iui compounds;

As shown in my patents, the suibhurizatienmay' beadvantageously"effected by gradually adding thesulphurtopreheated"spermpiI (or l-ilem'ono-= esters) and" maintainingthe" mixture Between- 300-380" F. until substantially all -of 't'hesulphur has combined. In such methods, naturally? oc curr-ing" monoesters such a s 'spermoil; etca;v are ordinarily claimed in my Patent2,'1-7'9;066. .,I-IoWever, as disclosed in my above patents, syntheticunsaturated aliphatic mono-esters-such aswobtained by esterifyingisuitable fatty acidsrwith appropriate alcohols ma-y likewise besulphurizedtoproduce sulphurized mono-esters;

there described} employed. this: being? specifically" thesetri-glycerides may be represented by the following formula:

wherein R represents the aliphatic group of a fatty acid which may besaturated or unsaturated. On the other hand, the main distinctionbetween fats (solid glycerides) and fatty oils (liquid glycerides) isthat the former are mostly glycerides of saturated acids, whereas thelatter are mostly glycerides of unsaturated fatty acids. For instance,stearin, which is the main constituent of manyfats, is thetriglycerideofstearic acid. On the other hand, olein, which-is the mainconstituent in many fatty oils, is the triglyceride of oleic acid; afatty acid containing one double bond in the aliphatic chain'thereof.For instance, lard oil contains substantial amounts of olein. Thisparticular giyceride is also present in many other fatty oils,particularly the vegetable oils. However, vegetable oils also containglycerides of other fatty acids; including fatty acids containing 2 or 3double bonds in the aliphatic chain, such as linoleic,'linolenic, andsimilar acids. In fact, many oils contain substantial amounts of mixedfatty glycerides wherein the hydroxyl groups of the glycerine areesterified with 'difierent fatty acids, the three hydrcxyl groups beingsometimes esterified with three different acids respectively. Likewise,many fats also contain mixedglycerides, varying amounts of unsaturatedfatty acids being sometimes present in addition to saturated acids. Suchrrnxed glycerides, upon hydrolysis, yield two or three different fattyacids. That is, ordinarily, fats and fatty Oils are not simpletriglycerides of fatty acids. Instead, they usually contain varyingamounts of mixed glycerides, in addition to one or more triglycerides ofsingle fatty acids of the type predominantly characteristic thereof,this being particularly true with most commercial animal or vegetableoils. In other words, commercial fats and oil are complex mixture ofseveral glycerides, and a wide varietyof fatty acids can be obtainedtherefrom.

Thus, by the present invention, a wide range and variety of sulphurizedmono-esters may be obtained by processing commercial fatty oils andmixtures thereof according to my improved processes.

In my improved methods of making sulphurized mono-esters, I firstsulphurize the fatty oils or glycerides with sulphur, so as to obtainsulphur addition products, and then convert these sulphurized glyoeridesinto the desired sulphurized mono-esters by reaction with monohydricalcohols, usually in the presence of a catalyst such as sulphuric acid.The sulphurized mono-esters so obtained are separated from the glycerineand may be further refined, if desired. Likewise, the separatedglycerine is recovered and may also be I refined as desired. In thisway, I obtain valuable glycerine as a by-product, as well as desirable'sulphurized mono-esters; both products being high-grade materials.

In preparing the sulphurized fatty glycerides, a wide variety of fattyoils or other glycerides of unsaturated fatty acids may be employed. In

general, any fatty glyceride containing atleastone mol of unsaturatedfatty acid is useful in the present processes; tri-glycerides containing2 or 3- mols of unsaturated fatty acid being advantageous.

In particular, I find that fatty oils having iodine numbers ranging from70 to can be readily sulphurized and converted into sulphurizedmono-esters which are-particularly advantageous improvement agents forlubricating oils. Forexample, lard oil having an iodine number ofapproximately 72 yields particularly advantageous products whenprocessed by my new methods. While lard .011 contains substantialamounts of olein as the main constituent thereof, it also containsvarying amounts of glycerides of other fatty acids, some saturated andsome unsaturated, and the final product obtained from it is a mixture ofmono-esters of such acids; the sulphur being added to the double bond ofthe unsaturated acids. However, the products obtained from lard oilcontain relatively large amounts of monoesters of sulphurized oleicacid. In fact, olein is typical of the. glycerides of unsaturated fattyacids which are particularly useful and advantageous in the presentprocesses. However, I may also employ with advantage other glyceride andmixtures of glycerides having iodine numbers ranging from 70 to 130;many 'ofthe commercial fatty oils having iodine numbers within thisrange. Other giyceride mixture having iodine numbers within this rangecan be readily prepared by blending together various fatty oils. Forinstance, lard oil may be blended with other fatty oils, such ascottonseed oil, menhaden oil, soya oil, corn oil, tung oil,-linseed oil,and other oils having relatively high iodine numbers. That is, byselecting the fatty oils employed, or blending together various fattyoils, or both, final products having particularly advantageous propertiecan be readily obtained. V

In sulphurizing such fatty oils or glycerides,

. the reaction is so controlled as to produce sulphur addition compoundsand to prevent the formation of any substantial amount of hydrogensulphide. These sulphur addition compounds or sulphurized glycerides areformed by saturating all or part of the double bonds of the fatty acidradicals with sulphur. Accordingly, the amount of sulphur employed inthis reaction does not exceed that required for complete saturation ofall of such double bonds. Usually, Iemploy somewhat smaller amounts ofsulphur than are neces- 320 F. and then gradually adding the sulphurto'the hot oilin small closes, the sulphur being added at such arate asto maintain a steady increase in temperature to between 320 and 380 F.by the exothermic heat of. reaction. After, all

of the sulphur has been added and combined, the. sulphurized glycerideis cooled usually to approximately room-temperature.

In converting the sulphurized glycerides into the correspondingmono-esters, the sulphurized fattyoi-ls' aresaponified' and esterifiedwith monohydric alcohols, the sulphurizedglycerides being reacted withan excess of the alcohol, usually in the presence ofanacid catalyst. Anadvantageous catalyst is concentrated sulphuric acid,

fiux. After the sulphurized glyceride has been.

completely converted into mono-ester, the stirring is discontinued andthe mixture stratified into two layers, an upper ester layer and a.lower acid-glycerine layer. The two layers are separated and may berefined as described post.

Informing the sulphurized mono-esters, variousalcohols may be reactedwith the sulphurized glycerides and a wide range of sulphurized monoesters obtained. Advantageous products are obtained with primaryaliphatic alcohols, particularly the lower alcohols, such as methanol,ethanol, propanol, butanol', and pentanol. Particularly good productsare obtained with butanol. In general, other alcohols may also be used.For instance, branch chain alcohols such asiso-propanol iso-butanol,etc... may be employed. Likewise, secondary aliphatic. monohydricalcohols may be used, as. well as. primary alcohols.

In general, any monohydric alcohol may be reacted with the sulphurizedgl-yceride to form useful sulphurized mono-esters. and liberate theglycerine. After this reaction is complete, the reaction; mixture ispermitted to stratify into an upper mono-ester layer and a glycerinelayer. When sulphuric acid or other acid is employed as a catalyst inthe reaction, the glycerine layer is.

somewhat acid, and the. separated glycer ne is usually further refinedto obviate this acidity before recovering the glycerine.

After the sulphurized mono-esters have been separated. from theglycerine layer, they are usually further refined by clay contacting. Indoing so, an appropriate amount of activated clay is added to thesulphurized mono-esters and the mixture agitated until the clay absorbsthe matter to be removed. The clay treated mixture is' then filterpressed to remove the clay and other insolubles. To facilitate suchremoval, filter aids may be added to the mixture prior to filtering. Forthis purpose, commerc al filter aidsv such as Supercel, .etc., areadvantageous. Furthermore, in refining the sulphurized. mono-esters, itis sometimes advantageous to treat them with lime to remove residualacidity prior to clay contacting. In such cases, the lime in excess ofthat necessary to obviate the mineral acidity, may be added and themixture stirred until substantially neutral. The calcium sulphate andexcess lime The sulphurizedrfatty" oils soobtainedare liquid materialsand can be readily converted into: sulphurized mono-esters.

' glycerine.

may'besettledl out: and filtered ofi prior to: clay; treatment.'Howeyen. complete;- removal pribnzto: clay treating issnot essential;and; inma-nyrcasesgthe liming and clay treatment.- may becombined: in.one. operation. In. such combination refining;

a small; amountv of lime: may. be. used. andi the activatedclay addedto; the mixture aften it; is: substantially. neutral; then: all of: the.insoluble: matter is: removed in.v one operation by: filter pressing; I1

In recovering and: refining the glycerine; the separated acid-glycerinelayer may beiprocessed'a in several ways. As stated ante, thisacidlayeris: usually neutralized with lime when. sulphuric. acid catalystisused.- Inrefining suchby-product glycerine, the glycerine; layer isadmixed with: an excess of hydrated; lime, in the form of a. slurry; andthe mixture agitateduntil; substantially neue tral. The so-treateds'glycerine is then. filter pressed to remove the calcium sulphate andexcess lime; 'I='herecovered glycerine is: a high: grade material; Itmaybe further refined, 'iff desired. For instance; the filtrate maybevacuum distilled to. recover substantially anhydrous: glycerine. All" ofthe various glycerine by-prod ucts. obtained in these processesareuseful, perse, for many purposes. 1 I

From the foregoing description, itwill be evi'-- dent that inthepractice of my invention, many;

. and various embodiments thereof may: be employed. In general, theseveral steps in my improved processes are interrelated andcorr-elatedto obtain highgrade sulphurizedmono-esters from-- fatty oils, withrecovery: of useful by-prod'uctr In the most advantageous embodi mentsthereof, my improved processes include reacting sulphur with fatty oilscontaining glycerides of unsaturated fatty acids to obtain sulphuraddition products thereof, reacting the sulphur-.. ized glycerides withmonohydric alcohol in the. presence of sulphuric acid to convert them.into sulphurized mono-esters, separating such monoesters from theglycerine, and refining the separated sulphurized mono-esters, usuallywith lime. and clay. Likewise in recovering and refining the, glycerine,the acid glycerine layer is treated with lime or otherwise refined toobtain pure glycerine. These and other embodiments of my invention arefurther illustrated in more detail by the specific. examples given post;

The following examples are illustrativeembodi ments of the methods andproducts broadly set {orth ante, and are not limitative of my invenion.

Erample'1;- Into a suitable vessel equipped. withmeans for agitating andfor heating and cooling the reaction mixture, there were charged" 88pounds of a mixture of fatty glycerides having aniodine number, of 89and prepared by.

blending together 55' parts of prime lard oil and, 45 parts of, crudecottonseed oil, by weight. The mixed oils were heated to approximately330 F. and 12 pounds of sulphur were gradually added: to the hot oil insmall doses over a period of approximately one-half. hour; thetemperature. being held between .340. and 350 F; during the introductionof the sulphur. After all of the sulphur was added, the reaction mixturewas maintained at said temperatures until the reaction was complete. Thesulphurized oil so obtained wascooled to approximately room temperature.The yield of sulphurized oil was substantially pounds;

The sulphurized glycerides" so obtained were agitator' and a refluxcondenser. While agitating the charge, a mixture. of 22 pounds'ofnormalbutanol and 5 pounds-of 96 per cent sulphuric acid wereadded and thisreaction mixture heated at 200220 F. for four hours. After the reactionwas complete, the gitation was stopped and the mixture Stratified intotwo layers, anupperester layer and a lower acid-glycerine layer,whereupon the acid-glycerine layer was drawn oil.

The sulphurized mono-esters so obtained had a slight acidity, due .toresidual mineral acid dissolved therein, and were treatedwith sufiicientlime to neutralize the mineral acidity; In'doing so, the sulphurizedmono-esters were "admixed with 2 pounds of hydrated lime and the mixtureagitated until a substantially. neutral product was obtained. The excesslime and other insolubles were settled out and removed. l

The substantially neutral sulphurized monoesters were then'furtherrefined by contacting with activated clay. .In-doing s0, 9'pounds ofactivated clay-were added to the sulphurized mono-esters and the mixtureagitated and maintained at 275 F. for about-2V2 hours. The; sotreatedmixture was then filter pressed to separate the clay from the treatedoil, a small amount of filter aid being used to facilitate theseparation. The filtrate so obtained was a mix ture of butyl esters ofsulphurized fatty acids and was a high grade improvement agent-forlubrieating oils and like lubricants; The detailed prop-;

erties of the initial glyceride mixture, the sulphurized glycerides andthe final refined sulphurized mono-esters were as follows:

The separated glycerine-acid layer weighed approximately pounds and wasfurther refined to recover glycerine. In doing so, the glycerine layerwas admixed with 4 poundsof hydrated charged into a suitablexvesszelfitted with an Original h Refined sulglyceride p phurized mixture mqmono-esters oravit miri 8.7 16.4

Viscosity, SUV, seconds: a

0010f, NPA Sulphur, B, per cent Here again, the separated glycerine-acidlayer. was refined to recover, high grade glycerine, as described inExample 1.

In the foregoing examples, blends of two fatty oils were employed inpreparing mixtures of glycerides having iodine values advantageous forthe present purposes.- Likewise, I may blend several oils to obtainother mixtures which are advantageous starting materials for my presentprocesses. This is indicative of the versatility of the presentinventionand is further illustrated post. V

Further, mineral oils may be also incorporated in the sulphurized oilsduring the processing. For instance, mineral lubricating oils may beadmixed with thesulphurized mono-esters prior to refining themwith clay.Such embodiments of my invention are illustrated in the following ex JEa'ample 3.--A mixture of fatty glycerides having an iodine number of91.6 and prepared by blending together 58.6 per cent of lard oil, 20.7per cent of cottonseed oil, and 20.7 per cent of soybean oil, by weight,was processed by the following procedure:

Into a suitable vessel there were. charged 88 pounds of the aboveglyceride mixture and after heating to 340 F. with stirring, 12 poundsof sulphur were gradually added. The heating was continued until all ofthe sulphur was combined. The sulphurized oil so obtained was cooled toapproximately room temperature and then admixed with acidulated alcoholprepared by blending 25 pounds of normal butanol and 5 pounds of 96 percent sulphuric acid. After the addition, of the acidulated alcohol, themixture'was then heated to ZOO-220 F. for four hours. After thesaponilime and agitated until the sulphuric acid was neutralized. Themixture was then settled and filtered to separate the substantially purglyc-- erine from the calcium sulphate and excess lime. The recoveredglycerine' maybe further refined,

such .as by vacuum distillation or otherknownv methods, if desired. v

Example 2.-Another superior improvement agent comprising a mixtureofbutyl esters of sulphurized fatty acids was obtained by processing 88pounds of a mixture of fatty'glycerides having an iodine number of 89'and comprising 80 per' cent prime lard oil and 20 percent of menhadenoil by weight, according to the proceduregiven in Example 1 ante; thismixture of lard and menhaden oils being sulphurized with 12 pounds of'sulphur, the sulphurized glycerides reacted with acidulated normalbutanol, and'the sulphurized mono-esters separated from the glycerineandrefined by clay contacting as described in Example l.v j e Theproperties of the initial glyceride mixture, the sulphurized glyceridesand the refined sulphurizedrnonoester were as follows:

(ill

fication andesterification were complete, the mixture was stratifiedinto an ester layer and glycerine layer and the g'lycerine layerwithdrawn. The ester layer' was'then diluted with an equal weight ofmineral lubricating oil, namely a Pennsylvania oil having a viscosity of70 seconds (SUV) at F. This oil mixture was then clay con-' tacted at275 F. for two hours and filter pressed through a inch layer ofSUIleICBI. The filtrate was a clear solution of butyl esters ofsulphurized fatty acids dissolved in the'min'eral lubricating o l. -Itis an excellent lubricant, per se. Also, it may be further diluted withlubricating oil to prepare other lubricants. 1

The separated acid-glycierine layer was also recovered and refined asdescribed in Example 1. In the above example, in lieu of the particularmixture of fatty oils employed ante, other blends of fatty oils may beemployed. In this way, a wide range of sulphurized mono-esters can be.readily. obtained. This is further illustrated in Table 1, wherein theproperties of the sulphurized products obtainable fromblends of severalfatty oils bythe procedure of Example 3 are given, together withthecomposition of the glyceride mixtu'res. from which they were obtained. a

Table -I Mix- Mix- Mix- Mixture ture ture ture No. 1 No.2 No.3 No. 4

Make-up, per cent by weight:

Prime lard il. Crude cottonseed oil Crude soya bean oil Winter pressedfisho Refined peanut oil No. 3 castor oil Beef tallow.

Raw linseed oil Glyceride mixture: Inspection- Gravity, API 22. 6. '22.0 20.1 23.0

Viscosity, S UV, 210F-. 63. 3 56. 4 61.0 53.7 Pour, F. +35 +40 +30 5Color, NPA 4. 75 2. 25 5. 5 '2. 25 Neutralization No l. 56 5.00 3. 48 2.Iodine N 0., Mod..Hanus. "91. .6 86. '7' 89. 2 86. 8 Sulphnrlzed oil:

Inspection:

Gravity, ARI. 8. 8 8. 7. 7 l0.'1 Viscosity, SU V,100F .1, 090 1, 782 1,265 i803 Sulphur, B, per cent l1. 3 11. 9 l1. 6 12.2

Neutralization No 0192. 352 2.120' 1.76 Finished clay-treatedsulphurized esters:

Inspection:

Gravity, API. 25. 5 25. 7 24. 9 25.8 Viscosity, SUV:

100 F 99.4 06.3 110. 6 92.4 210 F I 40. 3 '40. 3 40. 5 40. 3 Flash, 00 F355 360 355 .355 51m, (2 F 95 4400 95 figO our, 25 5 Color, NPA 4. 755.0 6. 0 5. 5 -Sulphur, =B, per cent 4.84 4. 72 4. 89 4.62

Other blends of various fatty oils may be employed as iazstartingmaterial in the present processes. However, the present invention is'notlimited to the use of blended oils. In fact, advantageous products canbe obtained from various natural fatty oils or .g'lycerides havingiodine values between 70 and 130. For instance, lard .oilis anadvantageous starting material. It-can be readily sulphurized andconverted into .sulphurized mono-esters, as illustrated in the followingexample.

Example .4..In this embodiment of my invention, 332 pounds of prime"lard oil were heated to "320 F. and "45 pounds "of sulphur weregradu'ally added to the hot oil 'in 'small doses over a period of twoand one-half "hours. After all of 'the sulphur was added, the mixturewas further heated .at 320-350 1F. for ten hours, and then'co'oledt'o'room temperature. A yield of 374 pounds of 'sulp'hurizedlardoil was obtained.

"The .properties of the original lard oil and the sulphurized glycerides"obtained therefrom were asfollows:

: Sulphur- Original lardoil 1 I gycendes Gravity, API 9.5

Viscosity, SUV, seconds, 100 F Pour, F Color, NPA Iodine number, .HanSulphur, B, percent Neutralization number Saponification.uumber m Thesulphurizedlard 'oil having the above properties is advantageous "inthat it 'can be readily converted into .sulphurized mono-esters byreaction with various alcohols.

In making .butyl esters .from the 'above sulphurizedrglycer-ides, 300pounds of the sulphurized lard oil were admixed with 85 ,pounds' ofacidulated butyl alcohol prepared by admixing 15 pounds of 96 per centsulphuric acid with .70 pounds of butanol. This reaction mixture wasagitated and gradually heated to 220 F. in approximately one andone-half hours, and then maintained at this temperature for four hourswhile continuing the agitation. After the reaction was complete, thestirring was discontinued and the mixture 'stratified into an esterlayer and a glycerine-acid layer. The glycerine layer was withdrawn and339 pounds of the sulphurized mono-esters so obtained were admixed with15 pounds of lime and '40 pounds of activated clay and the mixturemaintained at 275 F. with agiation "forthreehours. After this claycontacting, the refined sulphurized mono-esters were filter pressed toremove the clay and other insoluble matters. The filtrate was anexcellent improvement agent for mineral oils and lubricants.

The separated glycerine-aoid' layer weighed approximately 45 pounds andwas further treated to recover the glycerine. 'Inrefining the glycerinelayer, the procedure described in Example 1 was employed; the.glycerine-acid mixture being 'limed and the so-treated vglycerine being.filtered Table II Alcohol use'ciigolr 'esterificamButamfl v "lggggtli-Methanol Clay-treated s 111 phurized ester: Gravity, API i :16. 7 171.0-14. 6 Viscosity, SUV, seconds:

100" F 217 "201 159 210 00.3. .51. .1 .46. 8 Flash, 0 "F 410 375 360Fire, 00, F 445 420 405 Sulphur, B, per cent 9. 79 19.76 -.9.:80

The sulphurizedmono-estercom-positions given in the above table aremerely illustrativeof certain embodiments of this invention, and otheralcohol esters of sulphurized fatty acids can be prepared in likemanner. Also,minera'1 oils such as the usual grades of lubricating oil,may be incorporated with the sulphurizedmono-esters during theprocessing. Suchoils may be advantageously admixed with the sulphurizedmonoesters :prior .to clay refining, as in this way concentratesorlubricants can be directlyobtained. For instance, in the embodimentsillustrated in Examples 1, 2 and 4, varying amounts of minerallubricating oil, advantageously a Pennsylvania base neutral oil having.a viscosity of .7.0 (SUV) at F., may be readily incorporated prior tothe clay treatment, and the mineral oil solution of the sulphurizeolmono-esters then refined with clay to produce concentrated solutions,which are good lubricants and are useful in producing other lubricantscontaining small amounts of these improvement agents. :1 have prepared alarge number of suchmineral-oil compositions up and properties of a fewof them are given in the following Table III.

temperature over a perioclof 2.5 hours. Agitation Table III Sulphurlredmono-ester" visscrgsty, gif Grav- Flash Fire Sul- Prepared fromity, C, 0C, phur, per Per cent API F F per cent by by weight 100 F. 210 F.

Fatty oil mixture Alcohol 50 50 Lard oil and cottonseed oi1.. n-Butanol25.4 127 42. 7 365 440 4. 8 50 50 do Methanol 23. 7 299 55. 1 4. 3 50 50Lard oil and menhad n -n-Butanol 25. 0 134 44. 0 365 445 4. 9 50' 5OSoya been 011.... .I .do 23.1 61.1 440 495 5. 67 50 50 Ethanol 20. 381.9 445 500 6.89 50 50 n-Butanol 24. 3 295 56. 4 440 405 4. 30 50 50Ethanol. 23. 7 65. 6 4. 52 50 50 n-Butmlol 23. 1 378 61. 3- 425 475- 4.83 30 70 .....do....... 23.4 162.3 47.2 390 450 5.68 50 50 Isopropanol.26. 8 100; 7 46. 2 400 445 4. 30 50 50 n-Propanol.. 25. 3 227 51.8 420470 4.38 60 50 Ethanol... 22. (i 541 61. 9 420 475 4. 79 30 70 do... 21.8 177.7 48.4 380 430 6.5 50 50 do Methanol 25. 0 155.0 40. 0 390 440 4.80 50 50 Lard oil and soya been oil. n-Butanol... 24. 8 56. 2 4. 75

Example 5.-In a one-barrel stirring still equipped with a refluxcondenser, 300 pounds of sulphurized lard oil was treated with a mixtureof 70 pounds of normal butanol and pounds of 96 per cent sulphuric acidcatalyst. The acidulated alcohol was admixed with the sulphurized lardoil and the temperature raised to 220 F. over a period of 1 hours. Themixture was then maintained at 220 F. for 4 hours. At the conclusion ofthe treatment, the glycerine layer, amounting to 45 pounds, was drawnoff and 339 pounds of sour oil were obtained.

The sour oil was treated with the theoretical quantity of hydrated limenecessary to neutralize the mineral acidity, and the temperature wasraised'to 270 F. over a period of one hour. Filtrol was added and themixture contacted at 275 F. for three hours. The mixture was thenfiltered through a Sweetland filter press.

Properties of the clay-treated, sulphurized esters so obtained were asfollows:

Gravity, API 20.4

Viscosity, SUV:

210 F g 40.7 Flash, 00 F 350 Fire, 00 F' 400 Pour F.. +35 Color, NPA 6.5Sulphur, B .-per cent 8.90

The separated glycerine mixture was neutralized by pouring into a limeslurry containing 10 per cent excess lime, and filtered. The filtratehad the following properties:

Sp. gr., /60 F.. 1.147 Color Straw yellow and the sulphur was added tothe oil at this Prime lard Sulphurized oil lard oil Gravit API 23. l 9.5 S. gr'., 0lfi0 F 0. 9153 1. 0035 Viscosity, SUV, second F 193 210 F457 Pour, F +35 +55 Color, NPA..- 1. 5 Neutralization number. 1. 35 5. 8Sulphur, B, per cent..- 10.9 Iodine Nd. Hanus. 71. 5 Saponilicationnumber... 192. 5

The sulphurized lard oil was placed in a onebarrel stirringstillconnected with a reflux condenser and treated at F. with 92.5pounds (19 per cent by weight on the sulphurized lard oil) of formula 30denatured alcohol (91per cent of 190 proof ethanol and 9 per centanhydrous methanol) in the presence of 24.3 pounds of 103 per centsulphuric acid (5 per cent by weight of the sulphurized lard oil). Afteradding the acidulated alcohol, heating of the mixture was continued for11 hoursat -220 F. The sour oil was separated from theglycerine-sulphuric acidalcohol mixture by centrifuging, neutralizedwith a theoretical quantity of hydrated lime, and treated with twopounds of Filtrol per gallon of sulphurized ester at 275 F. for 2'hours.The claytreated product had the following properties:

All of the sulphurized mono-ester compositions, prepared by the examplegiven ante, are excellent improvement agents oils and like lubricants.By adding minor proportions of these mixtures of'sulphurized fatty acidmono-esters to mineral oil lubricants, say 0.1 to 20% by weight onthemineral oil, a wide variety for mineral lubricating :of. excellentimproved lubricants-.cambe prepared. '1' have preparedailargenum-ber-of;such=;improved lubricants containing theseisulphurized monoesters and :found by test that :they have manyadvantageousiproperties. The propertiesoflarfew of .such improvedlubricants rare a given a in the ."following Table IV.

Table J V zBase {Composition Properties .tion :'No.';1 i N 0.32; No.33

Gravity, API 31. l 31. 23153 31.20 Viscosity, ,SU.V:

100 -F 370 364 358. 369 210 F 58.9 58. 2 57. 8 58.0 Flash, 00, F 430 425440 430 Fire, 00, F 495 490 490 490 Pour, F 0 0 +5 Color, NPA 2. 25 2. 52. 25 2. 75 Sulphur, B. per cent 0.13 0. 05 0. 12 Copper strip test, 212F., 3 hr Falex wear test:

1,000 lb. gauge load, min.-

Wear, No. of teeth 5 4 Gauge load at seizure, lb 1, 900 1, 800 I, 800Sligh oxidation No l 3 4 3 Corrosion test, mod. Underwood:

Cadmium-silver bearing. Copper-lead bearing Oxidized oi1- Viscosity,SUV, 210 F 75.0 58.9 58.6 58.0 Viscosity increase 28. 6 1. 2 1. 4 0Carbon residue, per cent. 1. 02 0. 18 0. 18 0. l6 Sludge, per cent. 2.50 0.01 0.01 Nil 1 Passes. 2 Fails.

In the above table, the base composition contains only a high gradePennsylvania lubricating oil, it being included for purposes ofcomparison.

Composition No. 1 comprises the base oil plus 0.25 per cent by weight ofthe ethyl esters prepared from sulphurized lard oil.

Composition No. 2 comprises the base oil plus 0.25 per cent by weight ofthe butyl esters prepared from a sulphurized mixture of lard, menhaden,and peanut oils.

Composition No. 3 comprises the base 011 plus 0.25 per cent by weight ofthe ethyl esters prepared from sulphurized mixture of lard andcottonseedoils,

The above compositions are excellent motor oils. Other improvedlubricants can also be readily prepared, such as lubricants forautomobile gears. In fact, excellent automobile gear lubricants can bemade by incorporating from 5 to 10 per cent by weight of thesesulphurized mono-esters in a suitable base oil. The properties of twosuch gear lubricants, together with those of the base oil employed, aregiven in the following Table V.

Table V Gear Gear lubr'i; 5 lubrtizcan can No. 1 NO 1 No. 2 No. 2

Gravity, API 27. 6 26. 8 27. 2 26. 4 Viscosity, SUV: 100 F 1, 182 2, 1901, 910 102. 8 163. 0 141. 3 455 525 475 530 620 540 +10 +5 +10 Color,NPA 3. 75 4. 75 4. 5. 0 Sulphur, 13, per cent n 0. l4 0. 95' 0.16 0. 85Sulphur added, combined, per

cent 0.81 0.81 Carbon residue, per cent 0.33 0.35 0, 0. 41 Copper striptest, 212 1 X, 3 h Centrifuge test:

Separation, per cent 1500 RPM, room temp, 2hr Trace Trace Trace TraceAlmen test, lever load, pound 8 16+ 6 16+ Timken test, lever load,pound. 12 42+ 14 42+ 1 Passes. 1 SI. tarnish fatty oils or mixturesthereof, with recovery ofuseful vby-zproduct glycerine. I v

Accordingly,- 'in the broad I practice of the present invention, inaddition to the specific embodiments that are given ante, other anddifferent embodiments within its generic scope may be employed.

What I claim is:

1. In the manufacture of sulphurized monoesters, the improvement whichcomprises reacting a sulphurized glyceride with a monohydric aliphaticalcohol acidified with sulphuric acid to completely liberate theglycerine from said glyceride and to convert the same into sulphurizedfatty mono-esters of said alcohol, and separately recovering thesulphurized mono-esters and glycerine so obtained.

2. In the manufacture of sulphurized monoesters, the improved processwhich comprises heating sulphurized glycerides with a monohydricaliphatic alcohol in the presence ofsulphuric acid until saidsulphurized glycerides are converted into sulphurized fatty mono-estersof said alcohol and the glycerine is completely liberated therefrom, andseparately recovering the sulphurized mono-esters and glycerine soobtained, the said sulphurized mono-esters and the glycerine beingsubsequently refined to neutralize and remove any residual sulphuricacidity.

3. The process of claim 2, wherein the glycerine is neutralized with anexcess lime and the neutral glycerine is filtered to remove the excesslime, calcium sulphate and other insoluble matter.

4. The process of claim 2, wherein the sulphurized mono-esters arerefined with activated clay.

5. In the manufacture of sulphurized monoesters, useful as improvementagents for mineral lubricating oils and lubricants, the improved processwhich comprises reacting sulphur with a fatty oil containing glyceridesof unsaturated fatty acids to form sulphur addition products thereof andthen converting said sulphurized glycerides into sulphurized mono-estersby reacting the so sulphurized fatty oil with monohydric aliphaticalcohol acidified with sulphuric acid to saponify the sulphurizedglycerides and convert the same' into sulphurized fatty mono-esters ofsaid alcohol, separating the glycerine so liberated from saidglycerides, and recovering and refining the sulphurized monohydricesters so produced to obtain substantially neutral sulphurizedmono-esters useful as improvement agents for mineral lubricating oilsand lubricants.

6. The process of claim 5, wherein said fatty oil is a non-drying oil.

'7. The process of claim 5, wherein said fatty oil is lard oil.

8. The process of claim 5, wherein said fatty oil comprises a mixture ofnon-drying and semidrying oils.

9. The process of claim 5, wherein said fatty oil comprises a mixture ofnon-drying and drying 10. The process of claim 5, wherein said fatty oilcomprises a mixture of lard oil and fatty oils having an iodine numbergreater than 130, the mixed oils having an iodine number between 70 and130. a

; 1'1.-The process of claim 5, wherein the fatty oil has an iodinenumber between 70 and 130.

12. In the manufacture of sulphuri'zed monoesters from fatty oils and'mixtures of fatty oils having an iodine number between 70 and 130 andcontaining glycerides of unsaturated fatty acids, the improved processwhich comprises heating such fatty oils with sulphur to form'sulphuraddi- 15 rtion products, reacting the sulphurized fatty oils withamonohydric aliphatic alcohol in the presence ofsulphuric acidto formsulphurized fatty acid mono-esters of said alcohol and to liberateg-lycerine, separating the acid glycerine from thesulphurized'mono-esters, refining the separated sulphurized mono-estersby contacting with acti vated clay and separatingthe refined sulphurizedmono-esters from the clay.

13.The process of claim 12, wherein the separated glycerine isneutralized with an excess of lime'and the neutral glycerine isseparated from the excess lime, calcium sulphate and other insolublematter.

, HERSCHEL G. SMITH.

